GXT grid column headers are not displayed for hidden columns once they are unhidden

I have a grid in GXT with few hidden columns. When I un-hide these hidden columns, the data is displayed in the grid bit, the column headers are not displayed. This is happening in all browsers. Please refer the below screenshot. I am trying to unhide Group ID and Asset ID columns, data group_ and asset_ is displayed in the grid but, in headers column it is not displayed. Can someone help me with this?